This invention relates to a new roof structure and the method for making it.
Existing methods of applying insulating and/or sealing membranes to flat and slightly sloping roofs have several disadvantages. The hot or cold adhesives employed heretofore are diffucult to apply properly in the field, and are subject to deterioration by weathering and by fire. Usually the head of the mechanical fastener employed projects above the insulation layer, resulting in a condensation points on the interior of the roof and a focal point for patch ice to form on the exterior surface. The use of elastomeric or plastic membranes as a top surface layer on the roofing materials has not been very successful due to the dependency on field application of adhesives to fasten the membranes to the substrate and the lack of a dependable method for joint sealing in the field.